The present invention relates to fixtures for dispensing sheet material from rolls, and more particularly to dispensers that are adapted for feeding from a presented roll, and from a spare roll following exhaustion of the presented roll, as in toilet tissue dispensers and the like.
Dual roll sheet dispensers are well known, being disclosed, for example, in U.S. Pat. Nos. 3,387,902 to Perrin et al., 3,770,222 to Jespersen, 4,422,584 to Dashnier et al., and 4,422,585 to Schultz et al. Typically, such dispensers have one roll supported in a first dispensing position, and an additional roll is held in a reserve position and moved to a second dispensing position (which in some cases is the same as the first dispensing position) following or upon exhaustion of the first roll. Perrin et al. disclose a U-shaped mandrel assembly having mandrel components that are movable in a rigid yoke member, the assembly being loadable with rolls having split cores. Once the mandrel assembly is loaded into the dispenser, the respective rolls are locked in respective dispensing and reserve positions until the dispensing roll is exhausted, whereupon its core is burst automatically by spring action of the mandrel assembly, whereupon the assembly is allowed to fall to a lower position within the dispenser, whereby the mandrel components for the exhausted roll move to an exhausted position and the remaining roll moves from the reserve position to a secondary dispensing position.
Jespersen discloses a roll paper dispenser having a pair of generally L-shaped guide channels for opposite ends of a pair of mandrels, with movable members of the dispenser permitting downward movement of the mandrels in a prescribed manner, with the dispensing position shifting in response to consumption of the lower roll until the respective mandrel becomes disengaged from the guide channels, whereupon the upper mandrel is released from the reserve position.
Dashnier et al. disclose a dispenser having a pair of oppositely cantilevered mandrels that are pivotally supported on a common axis in a manner permitting limited relative angular movement, the upper mandrel being detented in the reserve position until dislodged therefrom by movement of the lower mandrel, such movement being blocked until the lower roll is nearly consumed. Shultz et al. disclose a similar dispenser wherein first and second mandrels are each cantilevered from respective guide blocks that slide in respective legs of an L-shaped track. The first mandrel is retained in the reserve position by interference between the blocks until the roll on the second mandrel is nearly exhausted.
The roll sheet dispensers of the prior art have not been entirely satisfactory for at least some of the following reasons:
1. They are wasteful in that they do not provide for complete consumption of one roll before initiating consumption of the reserve roll; PA1 2. They are not versatile in that they require special or proprietary roll configurations; PA1 3. They are awkward to use in that partially consumed reserve rolls must be removed from their mandrels and either discarded or reloaded onto a different mandrel, and the loaded mandrels must be carefully guided into engagement with tracks or other supports; and PA1 4. They are expensive to provide and difficult to maintain in that they incorporate complex mechanisms and interlocks. PA1 (a) providing a dispenser having a dual mandrel and a housing, the housing including a base portion and an openable cover portion having a closed position, opposite guide slots being formed between respective guide surfaces of the base portion and the cover portion in the closed position thereof for defining respective first and second dispensing positions, a reserve position, a pinch position, and an expended position for the rolls, the pinch position defining a restricted passage for the roll in a mostly expended condition thereof and being in a path between the first dispensing position and the expended position, the expended position defining clearance for free rotation of the roll in the mostly expended condition; PA1 (b) loading a pair of the rolls on respective portions of the mandrel; PA1 (c) opening the cover portion to an orientation wherein the guide surfaces thereof are upwardly facing; PA1 (d) lowering the mandrel into engagement with the guide surfaces of the cover portion; and PA1 (e) closing the cover portion with the rolls in the first dispensing and reserve positions thereof. PA1 (a) unrolling and separating sufficient material from the roll having the first dispensing position to attain the mostly expended position; PA1 (b) moving the mandrel until a portion thereof is in the expended position, the roll in the reserve position being thereby moved to the second dispensing position; and PA1 (c) retaining the roll in the second dispensing position.
Thus there is a need for a sequential roll sheet dispenser that overcomes the disadvantages of the prior art.